Fluorescent molecularly imprinted polymer based on sugarcane-derived carbon quantum dots for the detection of Chrysin

Chrysin (5,7-dihydroxyflavone) is a bioactive flavonoid whose selective detection in complex matrices remains challenging. Herein, a green fluorescent molecularly imprinted polymer (SCQDs@FMIPs) was developed using sugarcane bagasse–derived carbon quantum dots (SCQDs) as the core. SCQDs with excellent fluorescence were synthesized hydrothermally and functionalized with KH550 to enhance surface reactivity. Using chrysin as the template, SCQDs@FMIPs were prepared via a sol–gel process, exhibiting high photostability and specific recognition. The sensor achieved rapid fluorescence quenching within 5 min and a low detection limit of 2.54 × 10 −4  g/L, surpassing non-imprinted polymers. Mechanistic studies revealed dynamic quenching with partial FRET contribution. SCQDs@FMIPs displayed strong selectivity against structural analogs and ions, with satisfactory recoveries (73.43–128.06%) in real samples. This work demonstrates a sustainable, low-cost, and efficient strategy for chrysin detection, highlighting the value of agricultural waste in advanced sensing applications.